Combine like terms to simplify the expression: ${1.17-0.07a+(-3.92a)}$
Answer: Combine the $\text{{coefficients}}$ of the $a$ terms. $\phantom{=}{1.17{-0.07}a+({-3.92}a)}$ $=1.17+\left({-0.07}+\left({-3.92}\right)\right)\cdot a$ $=1.17+\left({-3.99}\right)\cdot a$ $=1.17-3.99a$ The simplified expression is $1.17-3.99a$